In ShortThe first U.S. branch of the YMCA started in Boston in 1851; there are now more than 2,500 locations nationwide, making it the country's largest nonprofit community service program. Each YMCA reflects the community it's in, offering differing services based on the area. Most include fitness areas with aerobic equipment, classes and racquetball and tennis courts. Many also have day care and after-school programs, as well as summer day camps.